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Synergistic effect of mediator–carbon nanotube composites for dehydrogenases and peroxidases based biosensors

Domenii publicaţii > Chimie + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: Adina Arvinte, Lucian Rotariu, Camelia Bala, Ana Maria Gurban

Editorial: Bioelectrochemistry, 76(1-2), p.107-114, 2009.

Rezumat:

Very sensitive, low cost and reliable NADH and H2O2 sensors were realised and used for development of enzyme based biosensors. The active surface of the electrodes was modified with a nanocomposite obtained by modification of SWNT with a proper mediator: Meldola Blue (for NADH) and Prussian Blue (for H2O2). Low applied potential of − 50 mV vs. Ag/AgCl reference electrode proved the synergistic effect of nanocomposite materials towards NADH and H2O2 detection. Biosensors for malic acid and alkylphenols have been developed, using mediator-functionalised-SWNT-based electrodes and two different classes of enzymes: NAD+-dependent dehydrogenases and peroxidases. Immobilization of the enzymes was realised using a series of different procedures — adsorption, Nafion membrane, sol–gel and glutaraldehyde, in order to find the best configuration for a good operational stability. A higher sensitivity comparing with other reported biosensors of about 12.41 mA/M·cm2 was obtained for l-malic acid biosensor with enzyme immobilised in Nafion membrane. Phenol, 4-t-octylphenol and 4-n-nonylphenol were used as standard compounds for HRP based biosensor. Fast biosensor response and comparable detection limit with HPLC methods were achieved.

Cuvinte cheie: biochimie, electrochimie, biosenzori // biosensors, electrochemistry, biochemistry